Chicken or egg; does MS lower vD levels or does low vD levels make MS worse? #MSBlog #MSResearch
"Chicken or egg; what came first? The following study demonstrates that MSers with progressive disease have lower vD levels than RRMSers. Why? Could it be that progressive MSers have less sun exposure, or different diets, as a result of their disability? Until we do an adequately controlled trials we won't know if vD deficiency is caused by active MS, or vD deficiency drives MS disease activity and makes MS worse. Is vD the causative agent, or is reverse causation more likely? The latter refers to the consumptive vitaminopathy hypothesis; i.e. the more active your immune system is the more it consumes vD and lower your blood levels of vD. If the latter is the case giving vD supplements to MSers will have no effect on MS disease course. Why then do we recommend vD supplements to our patients? We do this for bone health and not MS."
"There are several ongoing trials of vD supplementation in MS. I am not sure if these trials will give us a definitive answers regarding vD being disease-modifying; based on my own calculations these trials are underpowered to give a definitive answer. Finally, it vD may not be what is important but actual sunlight exposure; low vD levels are a marker of a lack of sunlight exposure. There is immunological data suggesting that exposure of lymphocytes to UV-light in the skin is immunomodulatory and the low vD levels are simply an association. What is clear is that there are many questions that need answering in relation to vD and MS. It is a great pity that the community has not be able to get the needed funding to do the definitive experiment."
"You may find my previous presentation on this topic helpful."
Epub: Thouvenot et al. Vitamin D is associated with degree of disability in patients with fully ambulatory relapsing-remitting multiple sclerosis.Eur J Neurol. 2014 Dec 20. doi: 10.1111/ene.12617.
BACKGROUND AND PURPOSE: Vitamin D deficiency is a recognized risk factor for multiple sclerosis (MS) and is associated with increased disease activity. It has also been proposed that the lower the vitamin D levels are, the higher is the handicap.
METHODS: To refine the links between vitamin D insufficiency and disability in MSers, a retrospective cohort analysis was performed including 181 MSers prospectively followed without previous vitamin D supplementation, and age, gender, age at MS onset, MS type, MS activity, Expanded Disability Status Scale (EDSS) were analysed in correlation with plasma vitamin D levels.
RESULTS: Vitamin D levels were significantly higher in relapsing-remitting MS than in progressive forms of MS in multivariate analyses adjusted for age, ethnicity, gender, disease duration and season (P = 0.0487). Overall, there was a negative correlation between vitamin D level and EDSS score (P = 0.0001, r = -0.33). In relapsing-remitting MS, vitamin D levels were only correlated with disability scores for EDSS < 4 (P = 0.0012). MSers with >20 ng/ml of vitamin D were 2.78 times more likely to have an EDSS < 4 (P = 0.0011, 95% confidence interval 1.49-5.00).
CONCLUSION: Data support previous work suggesting that vitamin D deficiency is associated with higher risk of disability in MS. Vitamin D levels also correlated with the degree of disability in fully ambulatory patients with relapsing-remitting MS. These additional results support the pertinence of randomized controlled trials analysing the interest of an early vitamin D supplementation in MS patients to influence evolution of disability.
Labels: consumptive vitaminopathy, Vitamin D